Faas began his photographic career in 1951 with the Keystone Agency, and by the age of 21 he was already covering major events concerning Indochina, including the peace negotiations in Geneva in 1954.

[2] Faas is also famed for his work as a picture editor, and was instrumental in ensuring the publication of two of the most famous images of the Vietnam War.

In September 1990, freelance photographer Greg Marinovich submitted a series of graphic photos of a crowd executing a man to the AP bureau in Johannesburg.

In retirement he organised reunions of the wartime Saigon press corps and ran international photojournalism symposiums.

[6] Carl Robinson, a former Associated Press photo editor in Saigon during the Vietnam War, alleges that Faas had told him to change credit for the famous "Napalm Girl" image from having been taken by a photo stringer (freelance photgrapher) to AP photographer Nick Ut, who had also been at the scene and taken similar photographs.